Applying ecological principles to ecological systems
Plants and animals depend on each other for survival. They are effectively connected to each other through a web of interactions which, at the larger level, form a series of ecosystems and help shape the landscape. Individual species are easiest to conserve when they are maintained within their natural habitats and landscapes. Therefore, to conserve biodiversity, we must consider landscapes and their management as a whole.

Size
Human activity in Victoria has fragmented many of our natural ecosystems and landscapes. Any area of native vegetation, whether mallee scrub, coastal heathland or mountain forest, is more susceptible to damage if it is small and isolated from other natural areas. In the long term, large, consolidated areas of native vegetation are more viable than smaller, more fragmented areas. Large, intact areas of some ecosystems, such as Victoria’s grasslands and grassy woodlands, no longer exist. In future, some of these areas may be restored or re-aggregated in pastoral areas as part of drought preparedness arrangements.

Links and corridors
Fragmented ecosystems support less species and genetic diversity. Links between fragments can allow otherwise isolated populations of flora and fauna to remain connected to populations elsewhere.

Links therefore maintain larger gene pools, contributing to evolutionary development and long-term viability.

For some animals, the ability to move between different parts of their habitat is a critical requirement of their life cycle. In urban and rural areas, corridors of native vegetation along rivers and roads are literally lifelines for these animals.

On the other hand, roads and clearings through forests provide convenient corridors for the movement of introduced predatory animals like foxes and invasive pathways for weeds.

Many fish rely on free movement up and down rivers.

For them, structures such as weirs can become impregnable obstacles. At larger scales, the extensive coastal and inland freshwater wetlands linked by waterways enable waterbirds to survive droughts.

Boundaries
The boundaries between ecosystems are where change is most active. There the ebb and flow of seasons and environmental cycles have the most influence. Rapid, sometimes irreversible, change occurs especially at the boundary between natural ecosystems and altered ones. These so-called ‘edge effects’ include progressive invasion by pest plants and animals, changes to soil conditions and water flows, increased exposure to wind and sun, and changes to fire patterns.

Risk management principles
Taking into account these ecological considerations, the following risk management principles can be identified from the IGAE and the National Strategies:

• The causes of a significant reduction or loss of biological diversity must be anticipated, attacked at the source, or prevented.
• Prevention is better than cure. Protecting ecosystems from damage is far more cost-effective than attempting rehabilitation once the damage is done. Besides, some ecosystem changes and losses of biodiversity (for example, extinctions) can never be rectified.
• The ‘precautionary principle’ (Principle 15 of the Rio Declaration on Environment and Development, to which Australia has agreed) provides a general guide to dealing with the uncertainty and risk involved in conserving biodiversity, in two main ways:

  When contemplating decisions that will affect the environment, the precautionary principle involves careful evaluation of management options ‘to avoid, wherever practicable, serious or irreversible damage to the environment, and an assessment of the risk-weighted consequences of various options’.

  When dealing with ‘threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation’.⁹

Applying risk management principles to biodiversity conservation and management
Biodiversity conservation involves both risk and uncertainty. Risk refers to events of known probability. By contrast, uncertainty refers to a situation where less is known, for example, about possible undesirable side-effects, and probabilities cannot be assessed. ‘Risk’ is often used loosely to cover uncertainty as well. It is important to remember that, when ‘environmental risk assessment’ is referred to, matters of uncertainty, such as the possibility of undesirable effects on genetic diversity, are often being identified as much as quantifiable risks.

The precautionary principle requires that there be caution in decision-making. However, the application of the principle does not by itself dictate whether or not a proposal will proceed: this requires a consideration of the issues outlined below.

Dealing with risk
In biodiversity management, unlike some other endeavours, there are as yet relatively few examples where we have adequate data to confidently and accurately assess risk – which is a first step in managing risk.

One encouraging example is the use of our climate records, coupled with our knowledge of aquatic systems, to calculate the approximate risk of riverine wetlands being exposed to inappropriate wetting and drying patterns resulting from changes to river regulation.

A risk management strategy involves assessing risks to biodiversity values, regularly recording the state of those values, and developing and implementing proactive *risk-minimising responses where possible. An example of such a strategy is attention to threatening processes under the Flora and Fauna Guarantee Act.

Managing risk should also take into account its wider dimensions. People do not perceive risk solely in terms of measures of impact, such as loss of natural units (hectares of forests, individual animals, etc.).

They also rank risks based on how well the process is understood, how the impact is distributed, and factors such as whether the species or communities threatened are charismatic. Because of this complexity, even when we have good data, biodiversity risk management is as much a matter of judgement as it is a science.

Dealing with uncertainty
It is easy to overlook the importance of uncertainty. With biological systems, there is an immense amount we simply do not yet know, especially as we move from the visible species to other smaller forms of life, and to ecosystems.¹⁰ Many subtler aspects of ecosystem functioning will probably never be understood.

By consciously recognising uncertainty, we are better able to be systematic in thinking through the likely consequences of our actions. This will help us to be more cautious about monitoring the actual outcome of our actions, and systematic in adapting our future actions to avoid bad environmental outcomes. The precautionary principle also reminds us to think early about the magnitude of any damage we might do, and to consider whether or not that damage might be irreversible and how it might be minimised. For example, with risks such as species extinction, early preventative measures are likely to be crucial.

Uncertainty means that successful biodiversity management is an iterative process. As we learn more, we can improve our approaches, reassess how we allocate resources, and change priorities. Biodiversity management has to be an open-ended, adaptive process which develops continuously as further information and experience is gained.¹¹

Development principles
To the principles of ecological management and risk management can be added a third and more general set of development principles derived from the National Strategy for Ecologically Sustainable Development, to which Victoria is committed:

Look forward

• The present generation should ensure that the health, diversity and productivity of the environment is maintained or enhanced for the benefit of future generations.

Share responsibility

• Along with the community, all levels of government have a clear interest and responsibility in conserving biodiversity. Furthermore, the shared responsibility of conservation groups, resource users, indigenous peoples, and the general community (including industry and other natural resource users) is vital for successful conservation.

Take wise, balanced and fair decisions

• The close, traditional association of Australia’s indigenous peoples with land and ecosystems should be recognised.
• Processes for and decisions about the allocation and use of Victoria’s resources should be efficient, equitable and transparent.
• Decision-making processes should effectively integrate both long-term and short-term economic, environmental, social and equity considerations.
• Decisions should recognise the need to develop a strong, growing, diversified and competitive economy.

  Use smart tools

  • Cost-effective and flexible policy instruments should be adopted, including improved valuation, pricing and incentive mechanisms.

  These principles together constitute a powerful basis within which we can undertake actions to conserve and use our biodiversity. They do not apply only to government. Aspects are relevant to all decision makers, whether in business, part of community groups or individuals.